线目标的缓冲区生成是缓冲区分析的基础和关键。结合栅格算法与矢量算法的优势,提出矢栅混合算法解决线目标的缓冲区生成问题。采用Douglas-Peuker方法对线目标进行重采样以加快缓冲区建立速度,用扫描线方法将线目标矢量数据转化为栅格形式,再采用膨胀原理生成缓冲区,通过扫描缓冲区栅格边界,提取有效矢量数据,进行求交运算,对缓冲区生成中的自相交多边形进行处理。
The line buffer generation is the bases and key of the buffer analysis. Vector-raster mixed algorithm is put forward to solve the line buffer generation problem, combined with the grid algorithm and vector algorithm advantage. Douglas-Peuker method is adopted to resample the line. The mixed algorithm completes the changing from vector data to raster data. The buffer zone will be generated by expansion principle. Scan the border of the raster zone and extract the vector data on the scan way which are necessary for the finally buffer polygon. Carry out the intersection operation. The self-intersection polygon is processed on the buffer generation.